16 



many forms of the original species must have succumbed and only 

 the hardier ones, possessing a perfect adaptation to the soil on 

 which they stopd and. its climatic conditions remained. As the 

 Anaheim disease organism became gradually more effective in its 

 work the different specific forms also perfected themselves and 

 became more fixed and more uniform in their varietal types for 

 the different soils and climates. 



The Vinifera species during this time, not being subjected to 

 such in influence, did not change much; it did not develop into 

 more specific forms, althpugh acquiring a good many varieties, 

 but which must be ascribed principally to the agency of man. 



The difference between Vinifera and the American species is 

 not as great as one might suppose at first thought. The great 

 variety of growth habits and combinations Vinifera presents in its 

 different forms, although all in a slighter degree than with the 

 different American species, leads one almost to suspect that all of 

 the latter have descended from the former. In this case we would 

 have to look at different Vinifera varieties as the incipient forms 

 of American species. (See "Origin of Species" by Charles 

 Darwin.) 



.Let us see now what special changes the grape vine under- 

 went in order to cope successfully with the Anaheim disease and 

 the severer climatic and special soil conditions. It has been 

 mentioned that the two principal species in the northern States, 

 Riparia and Labrusca, are exceedingly hardy to frost and shallow- 

 rooting and that the former, occurring more in the middle-west, 

 is extremely free-growing or is little affected in its growth by 

 coldness in the soil. In the southern States almost all species are 

 sluggish growers, more or less, which is indicated by the absence 

 of the rooting quality of their cuttings, besides they are mostly 

 deep-rooting. In the Rptundifolia we probably have the greatest 

 divergence from the original type, having lost all affinity in graft- 

 ing to other species and being entirely uniform in its varieties. It 

 occurs in a region where conditions for a rapid and rank growth 

 of the grape vine must be extremely favorable and therefore also 

 favorable for the development of the Anaheim disease. But it 

 could not inhabit the region or the soil where the wild Rupfestris 

 is found mostly; its too sluggish root-growth would incapaciate 

 it in the presence of the disease to draw sustenance from a coarse, 

 gravelly soil, in which the moisture settles down rapidly. The 

 Rupestris is a species of late development; its somewhat less uni- 



